The internal resistance of the DV20XL is 9-15 ohms I believe. Someone check this to be sure.
I ended up loading it at 10, 33, 75, 150, 390 and 510
I had about a dozen AudioAsylum inmates listening at the time and we simply flipped through the options to find the one that did Ricki Lee Jones voice the best on the system at hand.
I like 10 ohms the best because either the tweeters rolled off too fast or his other components were overly warm. Most everyone liked either 10 to 33 ohms in that system.
Use a different preamp, amp and speakers and the 150 to 510 might be necessary.
The fun thing about building it with easily replaceable resistors is you can fine tune your Piccolo to help the majority of your LP's sound their very best.
I love this Piccolo. I had an engineer at the place and he told me it was the quietest head amp he ever heard.
Jim Hagerman can definitely design a circuit! Just build the power supply to deliver quietly and musical magic will be in the mix.